HPV Vaccines: An Important Tool for STI Prevention

HPV vaccines represent a milestone in the fight against virus induced tumors. In the 10 years since the introduction of both bivalent and quadrivalent HPV vaccines, population-based comparison data with the pre-vaccine era and observational studies allowed us to assess the global effect on HPV infection, as well as associated disease, in countries that have implemented HPV vaccine public health programs. There is evidence that vaccination significantly reduces the prevalence of high-risk HPV types, the incidence of ano-genital warts, and high-grade cervical abnormalities. The nine-valent vaccine, firstly authorized in 2014, provides further opportunities in terms of prevention compared to the first generation products. With the inclusion of HPV types 31, 33, 45, 52, and 58, the vaccine could increase the protection against cervix cancers moving from about 70% (the proportion of cancers associated with HPV 16 and 18) to 90%. It is also estimated to provide a high reduction of the burden of pre-neoplastic cervical lesions from the current 46% to 82%. Moreover, there is an additional protection fraction regarding tumors involving the anus, vulva, penis, vagina, and oropharynx. A universal HPV vaccination program could greatly reduce the incidence of new HPV-related diseases by direct boys’ immunization but also by indirect protection of unvaccinated girls. Taking into account all HPV-related clinical outcomes, the more recent vaccine price and the 2-dose schedule, the extension of HPV vaccination to males could be cost-effective. Concluding, HPV vaccines appear to confer an advantage in terms of public health contributing to greatly reduce the burden of HPV-associated disease.